JPH0427249B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to polyester with excellent weldability. More specifically, the present invention relates to a novel polyester in which an Al element and a monocarboxylic acid are bonded. Polyester, represented by polyethylene terephthalate (hereinafter abbreviated as PET), is used not only as fibers and films but also as food containers and food packaging films due to its excellent mechanical properties, transparency, heat resistance, electrical properties, etc. Demand is also increasing. By the way, when polyester is used as a food container or food packaging film, it itself has a certain degree of gas barrier property and is preferable for food preservation, but depending on the food to be filled or enclosed. Furthermore, improvements in gas barrier properties are required. Therefore, in order to improve the gas barrier properties, attempts have been made to create containers and films with multilayer structures in which gas barrier resins such as ethylene-vinyl alcohol copolymers and polyvinylidene chloride are laminated on polyester. However, the welding between the polyester and the above-mentioned gas barrier resin was extremely poor, and delamination easily occurred, making it impractical for practical use. Therefore, the current situation is that there is a strong demand for improving the adhesion when manufacturing such multilayer molded products. The present inventors investigated various modifications of polyester for the purpose of improving the adhesion between gas barrier resin and polyester, and found that an aluminum-containing polyester obtained by adding a special aluminum organometallic compound during polymerization of polyester. The inventors have discovered that this object can be achieved, and have arrived at the present invention. In addition, the polyester of the present invention not only has excellent adhesion to gas barrier resins, but also has high adhesion to polyolefins modified with carboxylic acid or its anhydride and ethylene-vinyl acetate copolymers. They also discovered that it has excellent adhesion to metals. That is, the present invention is based on the structural unit (In the formula, WR ₁ represents a divalent group excluding the carboxyl group of terephthalic acid, isophthalic acid, orthophthalic acid, or a straight chain aliphatic dicarboxylic acid having 4 to 10 carbon atoms, and D represents an aliphatic group having 2 to 6 carbon atoms. The table represents a divalent group obtained by removing the hydroxyl group from a diol or an alicyclic diol having 6 to 8 carbon atoms. Also, m and n are numbers that are 0 or 1 and satisfy m+n=1.) (In the formula, _R2 represents a monovalent group obtained by removing the carboxy group from an aliphatic or alicyclic monocarboxylic acid having 6 to 30 carbon atoms or an aromatic monocarboxylic acid having 7 to 20 carbon atoms.) The molar ratio of ():() is 1000:1~
100:5, and the molar ratio of ():() is 4:1 to
1:10, and each constituent unit is () and (),
It is bonded between () and (), and the intrinsic viscosity is
It is a thermoplastic polyester with a density of 0.5 dl/g or more. The unit represented by the formula (), which is the main structural unit of the polyester of the present invention, has 4 carbon atoms such as terephthalic acid, isophthalic acid, orthophthalic acid, succinic acid, adipic acid, azelaic acid, and sebacic acid.
A dicarboxylic acid selected from the group consisting of ~10 linear aliphatic dicarboxylic acids and ethylene glycol, trimethylene glycol, 1,4-butanediol,
Selected from the group consisting of aliphatic diols having 2 to 6 carbon atoms such as pentamethylene glycol, 1,6-hexanediol, diethylene glycol, and triethylene glycol, and alicyclic diols having 6 to 8 carbon atoms such as cyclohexanediol and cyclohexane methanol. This is an ester unit obtained by condensation with a diol. Even if the dicarboxylic acid and diol components are each composed of a single component, two
It may be composed of more than one type of component. The unit () constituting the polyester of the present invention is an aluminum atom. Aluminum is a trivalent metal element and has three bonds, at least one of which is bonded to (). That is,

[Formula] Naru alkoxyside combination and/or

() and () are bonded by a carboxylate bond of [formula]. And the molar ratio of ():() is 1000:1 ~
It is necessary that the ratio be in the range of 100:5. If () is less than this range, there will be little effect of improving adhesion, and if it is more than this range, the polymer may gel during polymerization, or a large amount of monocarboxylic acid is added to prevent gelation. This is not preferable because the chain-terminating effect of the acid lowers the molecular weight achieved. The units () constituting the polyester of the present invention are derived from monocarboxylic acids selected from the group consisting of aliphatic or alicyclic monocarboxylic acids having 6 to 30 carbon atoms and aromatic monocarboxylic acids having 7 to 20 carbon atoms. It is a monovalent group. Examples of such monocarboxylic acids include the following. Aliphatic monocarboxylic acids include caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid,
Linear saturated acids such as undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nondecylic acid, arahinic acid, as well as oleic acid,
It also includes unsaturated acids such as linoleic acid, linolenic acid, and arachidonic acid, and those having substituents such as 12-hydroxystearic acid and 2-ethylhexanoic acid. Examples of alicyclic monocarboxylic acids include cyclohexanecarboxylic acid, cyclopentanecarboxylic acid,
- Decalin carboxylic acid can be mentioned. In addition, aromatic monocarboxylic acids include benzoic acid,
Phenylacetic acid, diphenylacetic acid,

【formula】

[Formula] P-oxybenzoic acid and the like can be mentioned. Among these, linear saturated aliphatic monocarboxylic acids, benzoic acid and P-oxybenzoic acid are preferred. A monovalent group derived from these monocarboxylic acids ()
is at least due to the carboxylate bond ()
is combined with In order to improve adhesiveness, the polyester of the present invention needs to contain a certain amount of () as mentioned above, but since () acts as a branching agent, it is necessary to contain only () and (). In this case, the fluidity of the polyester is significantly impaired, or furthermore, it becomes gelled during polymerization, making it impossible to polymerize, making it impossible to obtain a practical polymer. In order to prevent this phenomenon and to make the fluidity and mechanical properties of the polyester preferable, the polyester of the present invention has a molar ratio of ():() of 4:
It is necessary that the ratio be in the range of 1 to 1:10. ()
If it is less than this range, the fluidity of the polyester cannot be maintained well, and if it is more than this range, it becomes difficult to polymerize polyester with a high degree of polymerization. The polyester of the present invention was prepared in a mixed solvent of phenol/tetrachloroethane (1:1 weight ratio) at 30°C.
The intrinsic viscosity measured is 0.5 dl/g or more, preferably 0.6 dl/g or more. If the intrinsic viscosity is less than 0.5 dl/g, a polyester with sufficient mechanical strength cannot be obtained. There is no particular restriction on the upper limit, but polymerization becomes difficult if it exceeds 2.0 dl/g. As mentioned above, the polyester of the present invention consists of the structural units (), (), and (), but if the amount is small, part of the dicarboxylic acid component and/or diol component of the structural unit () (preferably
10 mol% or less) can be replaced with other dicarboxylic acids, diols, polyhydric carboxylic acids, or polyhydric alcohols. Examples of such dicarboxylic acids for modification include oxalic acid, hexahydroterephthalic acid, 5-sodium sulfoisophthalic acid, chlorterephthalic acid, bromiterephthalic acid, dichloroterephthalic acid, dibromoterephthalic acid, bromiisophthalic acid, and naphthalene. Examples include dicarboxylic acids (each isomer), chlornaphthalene dicarboxylic acid, bromonaphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, and diphenyl-4,4'-dicarboxylic acid. Examples of diols include polyethylene glycol, polytetramethylene glycol, neopentyl glycol, 1,4-bis(β-hydroxyethoxy)benzene, 2,2′bis(P-β-hydroxyethoxyphenyl)propane, and bis(P-hydroxyethoxyphenyl)propane. -β-hydroxyethoxyphenyl) sulfone, etc. Furthermore, polyhydric carboxylic acids include trimellitic acid, trimesic acid, pyromellitic acid, etc., and polyhydric alcohols include glycerin, trimethylolpropane, pentaerythritol, hexanetriol-1,
2,6, trimethylolethane, trimethylolhexane, trimethylolbenzene-1,3,
5, tripropyrrolbenzene-1,3,5, and tributyrolbenzene-1,3,5. Furthermore, dimethylolpropionic acid and the like can also be used. The polyester of the present invention is prepared by combining dicarboxylic acid and diol, which are the raw materials for the structural unit (), or their ester-forming derivatives, in the presence of the organoaluminum compound described below, or by combining the aluminum compound and a monocarboxylic acid, which is the raw material for the structural unit (). Alternatively, it can be produced by polymerization in the presence of its ester. (Here, R ₃ represents a monovalent group excluding the hydroxyl group of an aliphatic, alicyclic, or aromatic alcohol. _{R 4}
is the above-mentioned R ₂ or a monovalent group excluding the carboxyl group of an aliphatic monocarboxylic acid having 1 to 5 carbon atoms, or a monovalent group excluding the carboxyl group of dicarboxylic acid monoesters, dicarboxylic acid monoalkali metal salts represents. Further, R ₄ represents a methyl group or a phenyl group, and R ₆ represents a methyl group, a phenyl group, or a monovalent group obtained by removing the proton of the hydroxyl group of an aliphatic alcohol. Furthermore, i, j, and k indicate the average value of each group bonded to the Al atom, i+j+k=3 and 0≦i≦2,
0≦j≦3, 0≦k≦3. ) The above aluminum compound can be used after the esterification reaction between the dicarboxylic acid and the diol has progressed and the carboxy group content in the reaction system has become extremely small, or after the transesterification reaction between the dicarboxylic acid ester and the diol is almost completed. It is preferable to add it to the reaction system at a temperature of 230°C or lower. In particular, the above-mentioned aluminum compound may deactivate a commonly used transesterification catalyst, so it is preferably added after the transesterification reaction is completed. It is preferable to add it by dissolving it in a diol. Note that the above aluminum compound can be produced by various methods well known to those skilled in the art, one example of which is shown in Examples. When a monocarboxylic acid or its ester is used together with the aluminum compound, it is appropriate to add it to the reaction system at the time of purchasing the raw materials or before the esterification or transesterification reaction. When a transesterification reaction is employed, it may be carried out immediately after the transesterification reaction. For the esterification reaction between a dicarboxylic acid and a diol or the transesterification reaction between a dicarboxylic acid ester and a diol, and the subsequent polymerization reaction, conditions normally employed for polymerization of polyester can be employed. That is, an esterification reaction between a dicarboxylic acid and a diol or a transesterification reaction between a dialkyl ester of a dicarboxylic acid and a diol is carried out at a temperature of 180 to 230°C in the presence or absence of a catalyst, and then antimony, titanium, Polymerization is carried out using a compound such as germanium as a catalyst at a temperature of 260 to 300°C and a pressure of 1 mmHg or less. The above-mentioned aluminum compound is added to the reaction system and at the same time R ₃ -O- group and

[Formula] Most of the group parts react and bond with the dicarboxylic acid or diol component, and the alcohol R ₃ OH or β diketone or keto acid R ₆ COCH ₂ COR ₅ corresponding to these groups is eliminated to form a distillate. move inside. In addition, in the R ₄ COO- group, R ₄ is R ₂ of formula ()
If it matches, a portion remains bonded to Al in the polyester, and the remainder undergoes an exchange reaction with dicarboxylic acid, is eliminated, and is bonded to the end of the polyester molecule. When R ₄ is a group obtained by removing the carboxy group from a monocarboxylic acid having 5 or less carbon atoms, most of the monocarboxylic acid or its alkyl ester migrates into the distillate. In this way, Al is bonded within the molecular chain or at the end of the molecular chain of the polyester. Since most of the added amount of Al combines with polyester, the amount of aluminum compound added above is limited to dicarboxylic acid.
A suitable range is 0.1 to 5 moles per 100 moles. Furthermore, the monocarboxylic acid that is the raw material for the structural unit () is based on the total amount of the R ₂ COO− group in the aluminum compound and the monocarboxylic acid or its ester, based on the number of moles of Al.
It is preferable to add it in an amount of 0.25 to 10 mol. It was confirmed from the facts described below that the polyester of the present invention can be obtained by the method described above. (1) R ₃ -O- group in aluminum compound and

[Formula] Amount of group and R ₃ OH and detected in distillate
The amount of R ₆ COCH ₂ COR ₂ is almost the same. (2) As a result of trace analysis using a 400MHz ultra-high resolution NMR spectrum, R ₂ COO- groups are present in the polyester, and the amount is the sum of the R ₂ COO- groups in the added aluminum compound and the monocarboxylic acid or its ester. Match the quantity. (3) Fluorescence X-ray analysis shows that Al atoms are present in the polyester in an amount approximately equal to the amount added. (4) As a result of FT-IR spectrum analysis of polyester, 1600cm, which is not seen in ordinary polyester.
^-1 and 590cm ^-1 new absorptions are observed. The absorption of the former is, for example, Analytical Chemistry, No. 24.
Vol., p. 635 (1952), the absorption of carboxylic acid aluminum salts, and the latter absorption is e.g.
Related Vibrations”, Edward Armold (London), this is absorption of metal alkoxides. From the above results, the above-mentioned aluminum compound undergoes chemical changes during the polymerization reaction process, and alkoxide bonds with diol components, dicarboxylic It is considered that the aluminum compound is converted into an aluminum compound having a carboxylate bond with an acid component and a carboxylate bond with a monocarboxylic acid component represented by the formula (), and is incorporated into the polyester molecular chain or at the end.This invention As mentioned above, polyester has excellent adhesion to gas barrier resins such as ethylene-vinyl alcohol copolymers and polyvinylidene chloride, polyolefins modified with carboxylic acids or their anhydrides, ethylene-vinyl acetate copolymers, and metals. It also has excellent adhesion to polyester, making it extremely useful as a constituent material for various laminates or as an adhesive. Polyester of the invention/gas barrier resin, polyester of the invention/carboxylic acid or its anhydride modified polyolefin or ethylene-vinyl acetate copolymer/gas barrier resin, conventional polyester/polyester of the invention/gas barrier resin, Combinations such as polyester/aluminum foil or sheet/polyolefin of the present invention can be mentioned.These laminates can be used as a film,
It can take various shapes such as sheets, hollow bodies, or cups, trays, and bottles obtained by molding these materials, and has excellent gas barrier properties, making it extremely useful for food packaging and storage. The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples. In addition, the melting point of the crystalline polyester in the examples was determined by DSC (differential scanning calorimeter). That is, the peak temperature of the crystal melting peak when 5 mg of the rapidly cooled film was heated from room temperature at a rate of 20° C./min was defined as the melting point. In addition, the glass transition temperature of the amorphous polyester was also determined by DSC. The temperature increase rate is 20℃/
It's a minute. Example 1 [Preparation of aluminum compound] A nitrogen gas introduction pipe, a stirrer, and a cooling pipe were installed.
100 ml of hexylene glycol is placed in a 300 ml round bottom flask while passing nitrogen gas, and 0.10 mol of aluminum isopropoxide powder is added at room temperature and stirred. Next, add 0.05 mol of caprylic acid and 0.15 mol of P-oxybenzoic acid, and put it in an oil bath while stirring.
Raise the temperature to 100℃. Continue the reaction at this temperature for 15 minutes. Thereafter, 0.10 mol of acetylacetone was added, and the reaction was continued at 100°C for 15 minutes to prepare an aluminum compound. As a result of measuring the infrared absorption spectrum of this reaction solution, although a slight absorption of unreacted carboxylic acid was observed at 1700 cm ^-1 , the absorption of carboxylic acid aluminum salt at 1600 cm ^-1 and the absorption of acetylacetone complex salt at 1540 cm ^-1 appears strongly, indicating that the alcoholate bond has changed to a carboxylate and acetylacetone complex salt bond. [Polymerization] A 300ml three-necked flask, a nitrogen gas inlet tube, a stirrer,
Attach the cooling pipe and add dimethyl terephthalate.
100g, ethylene glycol 68g, zinc acetate 40mg
is added, heated to 200°C under a nitrogen gas stream, and reacted for 3 hours to perform transesterification. Subsequently, 25μ of tributyl phosphate and 40mg of antimony trioxide were added at 200°C, and the above aluminum compound solution was added in an amount of 0.52 mol per 100 mol of dimethyl terephthalate in terms of aluminum atoms, to the contents of the flask. After dissolving the aluminum compound solution, the temperature of the oil bath was raised to 260°C, and the pressure was gradually reduced to 280°C, and polymerization was proceeded for 90 minutes under a reduced pressure of 0.1 mmHg to obtain a light-colored polymer. . The intrinsic viscosity ([η]) of the obtained polyester is
It was 0.71 dl/g. The melting point was 252°C. The NMR spectrum of the obtained polyester is shown in FIG. Absorption of the methylene group proton of caprylic acid at 0.90 ppm and the phenyl proton of P-oxybenzoic acid are observed at 6.65 ppm. The amount of caprylic acid present in the polymer determined from this spectrum was slightly smaller than the value calculated from the amount charged, but the amount of P-oxybenzoic acid present was
It almost matched the amount of preparation. FIG. 2 shows the FT-IR spectrum of the obtained polyester. Weak absorptions are observed at 1600cm ^-1 and 590cm ^-1 and are shown in Figure 3. This absorption is not observed at all in the spectrum of polyethylene terephthalate. As explained in the text, the absorption at 1600 cm ^-1 is based on carboxylic acid aluminum salt, and the absorption at 590 cm ^-1 is based on aluminum alcoholate. Example 2 A nitrogen gas introduction tube, a stirrer, and a cooling tube were attached to a 300ml three-necked flask, and dimethyl terephthalate was added.
Add 100 g of ethylene glycol, 68 g of ethylene glycol, 8.77 g of methyl benzoate, and 40 mg of zinc acetate, heat to 200° C. under a nitrogen gas stream, and react for 3 hours to perform a transesterification reaction. Subsequently, tributyl phosphate
25 μ, add 40 mg of antimony trioxide, add aluminum aceracetonate to dimethyl terephthalate
After adding and dissolving 0.50 mol to 100 mol, the temperature of the oil bath was raised to 260°C, gradually reduced to 280°C, and polymerization was carried out for 90 minutes under a reduced pressure of 0.1 mmHg. A yellow polymer was obtained. [η] of the obtained polyester was 0.70 dl/g.
Moreover, its melting point was 253°C. The FT-IR spectrum of the obtained polyester is shown in FIG. Absorption of aluminum carboxylate is observed at 1600 cm ^-1 and absorption of aluminum allate is observed at 590 cm -1 . In addition, as a result of NMR spectrum analysis of the distillate distilled after the transesterification reaction of this polyester until the end of the polymerization, absorption derived from acetylacetone was observed, and as a result of quantitative analysis, it was found that the added aluminum acetylacetonate An amount approximately corresponding to that of acetylacetone was detected. The above indicates that aluminum acetylacetonate releases acetylacetone during the polymerization process and changes to aluminum carboxylate and alcoholate. Example 3 [Preparation of aluminum compound] While passing nitrogen gas through the apparatus described in Example 1,
Take 100 ml of hexylene glycol, add 0.10 mol of aluminum isopropoxide powder, and stir. Next, 0.05 mol of caprylic acid and 0.15 mol of P-oxybenzoic acid are added, and the mixture is placed in an oil bath with stirring and heated to 100°C. Keep at this temperature and react for 15 minutes. Next, 0.10 mol of ethyl acetoacetate was added, and the reaction was continued at 100°C for 15 minutes to prepare an aluminum compound. [Polymerization] In the same manner as in Example 1, a transesterification reaction of dimethyl terephthalate and ethylene glycol was carried out, and 25μ of tributyl phosphate and antimony trioxide were added.
Add 40mg of the above aluminum compound solution to dimethyl terephthalate in terms of aluminum atoms.
Add aluminum in an amount of 0.52 mol to 100 mol, raise the temperature to 260°C, raise the temperature to 280°C while gradually reducing the pressure, and further reduce the pressure to 0.1 mmHg and polymerize for 90 minutes. I proceeded. The obtained polyester was pale yellow and contained no insoluble matter. The polyester [η] was 0.72 dl/g. In addition, the melting point of this polyester is 251℃
It was hot. Example 4 A nitrogen gas introduction tube, a stirrer, and a cooling tube were attached to a 300ml three-necked flask, and dimethyl terephthalate 70 was added to the flask.
g, 30 g of dimethyl isophthalate, 68 g of ethylene glycol, and 40 mg of zinc acetate were added, and the reaction was allowed to proceed at 200° C. for 3 hours under a nitrogen gas stream. Add 25μ of tributyl phosphate and 40mg of antimony trioxide, and add the aluminum compound solution prepared in Example 1 so that the amount of aluminum added is 0.52 mol based on 100 mol of the total of dimethyl terephthalate and dimethyl isophthalate in terms of aluminum atoms. and polymerized in the same manner as in the example. The obtained polymer was a transparent glassy polymer with a pale yellow edge. Tg is approximately 65 as measured by DSC glass transition temperature.
It was warm at ℃. Also, [η] of this polyester
was 0.70 dl/g. Example 5 A 300ml round bottom flask with a nitrogen gas introduction tube, a stirrer,
Attach the cooling pipe, 97g of dimethyl terephthalate,
Methyl benzoate 8.50g, ethylene glycol 57.4
g, 1,4-cyclohexanedimethanol 25.2
g, add 40 mg of zinc acetate, and add 200 mg of zinc acetate under a nitrogen gas stream.
The mixture was heated to ℃ and the transesterification reaction proceeded for 3 hours.
Tributyl phosphate 25μ, antimony trioxide 40
mg, 1.0g aluminum acetylacetonate
In addition, the temperature was raised to 260°C, the pressure was reduced to 280°C, the pressure was further reduced to approximately 0.1 mmHg, and polymerization proceeded for 90 minutes. The obtained polymer was a glassy polymer with a pale edge color, and [η] was 0.68 dl/g. DSC
The measured glass transition temperature was 78°C. Example 6 To a polymerization apparatus similar to Example 1, 100 g of dimethyl terephthalate, 100 g of 1,4-butanediol, and an n-hexane solution of tetrabutyl titanate were added so that the amount of tetrabutyl titanate was 40 mg.
Transesterification reactions were carried out at 180°C for 1 hour, at 200°C for 1 hour, and at 220°C for 1 hour. Next, the aluminum compound solution used in Example 1 was added so that the amount of aluminum added was 0.2 mol per 100 mol of dimethyl terephthalate, the temperature was raised to 260°C, the pressure was gradually reduced to 270°C, and the pressure was further reduced. The polymerization was carried out for 90 minutes at a pressure of about 0.1 mmHg. The obtained polyester was a pale yellow crystalline polyester with a melting point of 221°C. Also, [η] is
It was 0.73 dl/g. Example 7 64.0 g of bis-β-hydroxyethyl terephthalate, 25.0 g of succinic anhydride, 15.5 g of ethylene glycol, and 14.9 g of diethylene glycol were placed in the reaction apparatus described in Example 1, and the mixture was heated for 200 g under a nitrogen gas stream.
℃ and reacted for 1 hour, then heated to 215℃ and reacted for 1 hour.
Allow time to react. Add 25μ of tributyl phosphate and 36mg of antimony trioxide, add the aluminum compound solution used in Example 1 so that aluminum atoms are 0.50mol per 100mol of dicarboxylic acid component, and heat to 260°C while reducing pressure. 275℃,
Polymerization was carried out for 90 minutes under reduced pressure of about 0.1 mmHg. The obtained polyester was a hard rubber-like transparent light yellow polymer at room temperature, and had [η]=0.64 dl/g. Example 8 In a polymerization apparatus similar to Example 1, 64 g of bis-β-hydroxyethyl terephthalate and 36.5 g of adipic acid were added.
g, 15.5 g of ethylene glycol, and 14.9 g of diethylene glycol were added, and the esterification reaction was allowed to proceed at 200° C. for 5 hours under a nitrogen gas stream. Add 25μ of tributyl phosphate and 36mg of antimony trioxide, add the aluminum compound solution used in Example 1 so that the number of moles of aluminum atoms is 0.5 moles per 100 moles of the dicarboxylic acid component, and raise the temperature to 260 ° C. The temperature was reduced to 280°C, and polymerization was carried out for 1 hour under a vacuum of about 0.1 mmHg. The obtained polyester was orange in color and hard rubber-like. [η]=
It was 0.59 dl/g. Example 9 In the polymerization apparatus used in Example 1, 48.5 g of dimethyl terephthalate, 57.6 g of dimethyl sebacate, 8.77 g of methyl benzoate, 49.1 g of ethylene glycol,
Add 32.6 g of diethylene glycol and 40 mg of zinc acetate, heat to 200°C under a nitrogen gas stream, and perform transesterification for 3 hours. Then tributyl phosphate
Add 25μ, 40mg of antimony trioxide, and 1.0g of aluminum acetylacetonate, and raise the temperature to 260℃. The pressure was gradually reduced to 275°C, and polymerization proceeded for 120 minutes at a reduced pressure of about 0.1 mmHg. The obtained polyester was translucent, hard rubber-like, and had a pale edge color. [η]=0.56dl/g
It was hot. Comparative Example 1 [Preparation of aluminum compound] Attach a nitrogen gas introduction tube, stirrer, and cooling tube to a 200 ml round bottom flask, add 50 ml of hexylene glycol, and add powdered aluminum isopropoxide.
Add 10g of aluminum and raise the temperature to 120°C to distill off isopropanol and dissolve aluminum isopropoxide. [Polymerization] Using the same polymerization apparatus as in Example 1, 100 g of dimethyl terephthalate, 68 g of ethylene glycol,
Add 40 mg of zinc acetate, perform a transesterification reaction at 200°C for 3 hours under a nitrogen gas flow, add 25μ of tributyl phosphate and 40 mg of antimony trioxide, and add the above aluminum compound solution to 100 moles of dimethyl terephthalate. It was added in an amount of 0.52 mol, heated to 260°C, then raised to 280°C while reducing pressure, and polymerization was carried out for 90 minutes under reduced pressure of about 0.1 mmHg. The polymer began to wrap around the stirring rod after 60 minutes of polymerization time, and stirring was difficult in the latter stages of polymerization. The obtained polyester was pale yellow in color and contained a large amount of particulate insoluble gel. Comparative Example 2 [Preparation of aluminum compound] P was added to 50 ml of hexylene glycol using the reaction apparatus used for preparing the aluminum compound in Comparative Example 1.
-0.01 mol of oxybenzoic acid was dissolved, 0.05 mol of aluminum isopropoxide was added, and the mixture was heated to 100°C to react. The resulting clear solution was used for the next polymerization. [Polymerization] Instead of the aluminum compound solution of Comparative Example 1,
The aluminum compound solution obtained above was added in an amount of 0.52 mol of aluminum to 100 mol of dimethyl terephthalate, and polymerization was proceeded in the same manner as in Comparative Example 1. After 60 minutes of polymerization, conspicuous wrapping began to occur, making stirring difficult. The obtained polyester was pale yellow and contained a large amount of large insoluble gel. Comparative Example 3 [Preparation of aluminum compound] Using the same reaction apparatus as Comparative Example 1, xylene 50
ml, add 0.05 mol of aluminum isopropoxide, and heat to 100°C to dissolve. Next, 0.05 mol of acetylacetone was added and reacted for 15 minutes to obtain a light-colored, transparent solution. [Polymerization] Instead of the aluminum compound in Comparative Example 1, the aluminum compound solution obtained above was added so that the amount of aluminum was 0.2 mol per 100 mol of dimethyl terephthalate, and polymerization was carried out in the same manner as in Comparative Example 1. Polymerization time is 90 minutes. Again, a wrapping phenomenon was observed in the late stage of polymerization. The obtained polyester was pale yellow and contained insoluble gel-like particles. Comparative Example 4 [Preparation of aluminum compound] Using the same reaction apparatus as Comparative Example 1, 50 ml of xylene
Add 0.05 mol of aluminum isopropoxide and dissolve at room temperature. Then acetylacetone
Add 0.05 mol, raise the temperature to 50°C, and stir for 30 minutes.
Next, 0.10 mol of acetic acid was added and the mixture was reacted at 50°C for 30 minutes, and then the temperature was raised to 120°C to distill and remove isopropanol. [Polymerization] Instead of the aluminum compound of Comparative Example 1, the aluminum compound solution obtained here was used in an amount of 0.52 mol of aluminum per 100 mol of dimethyl terephthalate.
The polymerization was carried out in the same manner as in Comparative Example 1. At 60 minutes of polymerization time, a phenomenon in which the polymer was wrapped around the stirring rod occurred significantly, and the polymerization was stopped. The resulting polyester was pale yellow and contained insoluble gel particles. Comparative Example 5 Using the aluminum compound used in Example 1, polymerization was attempted to proceed in the same manner as in Example 1 by adding the aluminum compound in an amount of 10 moles per 100 moles of dimethyl terephthalate. However, when the temperature reached 260°C and the pressure was gradually reduced, it stopped flowing and turned into a gel. Example 10 The polyester obtained in Examples 1 to 5 and a normal polyester containing no aluminum compound as a comparative example
PET ([η] = 0.70) was heated using a heat press to a thickness of approx.
It was formed into a 200μ quenched film. In addition, sufficiently dried ethylene-vinyl alcohol copolymer (EVAL E manufactured by Kuraray, hereinafter abbreviated as EVAL)
A 100μ film was made from the chip. The two films were stacked and crimped at 180°C with a pressure of 10 kg/cm ² , then held at 280°C for 2 minutes under almost no load to melt and bond both polymers, and then lightly sandwiched in a cooling press to quickly cool the composite. A layered sheet was prepared. A rectangular specimen with a width of 15 mm was cut from this sheet, and after being left at room temperature overnight, a peel test was conducted at room temperature using an Instron universal testing machine at a tensile speed of 20 mm/min. The results are shown in Table 1. The polyesters obtained in Examples 1 to 5 were
Compared to PET, the peel strength at the melt-bonded interface with ethylene-vinyl alcohol copolymer is 10 times higher.
This is an improvement of nearly 40 times.

[Table] Example 11 Various aluminum compounds were prepared in the same manner as the method for preparing aluminum compounds described in Example 1, using 0.05 mol of various monocarboxylic acids shown in Table 2 instead of caprylic acid. The solution of this aluminum compound was added to 100 moles of dimethyl terephthalate by the polymerization method described in Example 1 so that the total amount of aluminum atoms was 0.52 moles, and the resulting polyester was processed using the polymerization method described in Example 10. A bonded sheet with EVAL was prepared and the peel strength was measured. The results are shown in Table 2.

[Table] Example 12 Multilayer films were prepared using the polyesters obtained in Examples 7, 8, and 9 and, for comparison, polyesters polymerized with the same monomer composition without adding an aluminum compound. i.e. biaxially oriented PET
The above-mentioned polyester is molded to a thickness of about 100μ on a film (thickness 100μ) at 180℃, and then
A 100μ film of EVAL was placed on it, melt-pressed at 180°C for 2 minutes (pressure: 5Kg/cm ² ), and rapidly cooled to produce a three-layer film. A specimen with a width of 15 mm was cut from this film, and a T-peel test was conducted at room temperature at a tensile speed of 200 mm/min. The results are shown in Table 3.

【table】 [Brief explanation of drawings]

Figure 1 shows the polyester obtained in Example 1.
This is an NMR spectrum. In addition, Fig. 2 shows Example 1.
FIG. 3 shows the FT-IR spectrum of the polyester obtained in Example 2, FIG. 3 shows the polyethylene terephthalate, and FIG. 4 shows the FT-IR spectrum of the polyester obtained in Example 2.

Claims (1)

[Claims] 1. Constituent unit (In the formula, R ₁ represents a divalent group excluding the carboxyl group of terephthalic acid, isophthalic acid, orthophthalic acid, or a straight chain aliphatic dicarboxylic acid having 4 to 10 carbon atoms, and D represents an aliphatic group having 2 to 6 carbon atoms. Represents a divalent group obtained by removing a hydroxyl group from a diol or an alicyclic diol having 6 to 8 carbon atoms.In addition, m and n are 0 or 1.
This is a number that satisfies m+n=1. ) (In the formula, _R2 represents an aliphatic or alicyclic monocarboxylic acid having 6 to 30 carbon atoms, or a monovalent group obtained by removing the carboxyl group from an aromatic monocarboxylic acid having 7 to 20 carbon atoms.) The molar ratio of ():() is 1000:1~
100:5, and the molar ratio of ():() is 4:1 to
1:10, and each constituent unit is () and (),
It is bonded between () and (), and the intrinsic viscosity is
Thermoplastic polyester of 0.5 dl/g or more.